It really depends on the firm and their existing approach to file storage. In legal, they call this a Document Management System (DMS). Some firms have a loose process, so they use this as a standalone app. Other law firms have 20+ years of files in their DMS, so they use this as an integrated feature.
The DMS providers have a great business and their product is stickier than glue. Fortunately, they are very startup friendly and have built out a whole app store ecosystem so other companies can layer on new capabilities that deepen the value of the DMS and make it even stickier.
The DMS providers have a great business and their product is stickier than glue. Fortunately, they are very startup friendly and have built out a whole app store ecosystem so other companies can layer on new capabilities that deepen the value of the DMS and make it even stickier.